Transcatheter closure of large postinfarct ventricular septal defect: Initial results of prototype Occlutech® device including the first-in-human.

BACKGROUND: Postinfarct ventricular septal rupture is a serious complication in delayed or failed reperfusion with a grim prognosis. The optimal timing and treatment option remain debatable in the absence of randomized controlled trials. Percutaneous device closure is a well-reported and less invasive treatment option but recent imaging studies indicate that majority of defects are too large to be adequately covered by the currently Conformite Europeenne and Food and Drug Administration approved occluder devices. METHODS: Six patients presented with large and complex postinfarct ventricular septal ruptures, considered unsuitable for the Amplatzer post-infarct ventricular septal defect Occluder, so were treated using the prototype Occlutech® 36 mm PI-VSD occluder, including the first-in-human use. RESULTS: The prototype device was successfully deployed in all patients with satisfactory immediate results and shunt reduction. Three patients (50%) in cardiogenic shock did not survive beyond discharge, of which two were complicated by device dislodgement or embolization. CONCLUSIONS: Percutaneous closure of large postinfarct ventricular septal ruptures is possible using newer device with a wider coverage. Further device refinement is necessary to improve treatment outcomes.

Analysing functional implications of differences in left ventricular morphology using statistical shape modelling.

Functional implications of left ventricular (LV) morphological characterization in congenital heart disease are not widely explored. This study qualitatively and quantitatively assessed LV shape associations with a) LV function and b) thoracic aortic morphology in patients with aortic coarctation (CoA) with/without bicuspid aortic valve (BAV), and healthy controls. A statistical shape modelling framework was employed to analyse three-dimensional (3D) LV shapes from cardiac magnetic resonance (CMR) data in isolated CoA (n = 25), CoA + BAV (n = 30), isolated BAV (n = 30), and healthy controls (n = 25). Average 3D templates and deformations were computed. Correlations between shape data and CMR-derived morphometric parameters (i.e., sphericity, conicity) or global and apical strain values were assessed to elucidate possible functional implications. The relationship between LV shape features and arch architecture was also explored. The LV template was shorter and more spherical in CoA patients. Sphericity was overall associated with global and apical radial (p = 0.001, R2 = 0.09; p < 0.0001, R2 = 0.17) and circumferential strain (p = 0.001, R2 = 0.10; p = 0.04, R2 = 0.04), irrespective of the presence of aortic stenosis and/or regurgitation and controlling for age and hypertension status. LV strain was not associated with arch architecture. Differences in LV morphology were observed between CoA and BAV patients. Increasing LV sphericity was associated with reduced strain, independent of aortic arch architecture and functional aortic valve disease.

Cerebrovascular Variants and the Role of the Selfish Brain in Young-Onset Hypertension.

BACKGROUND: Variants in the posterior anatomy of the cerebral circulation are associated with hypertension and lower cerebral blood flow in midlife (age ≈55 years); however, whether these variants are a result of aging or long-term exposure to high blood pressure is unclear. Additionally, the role these variants play in early onset of hypertension (<40 years) and poor cerebral perfusion in this population is unknown. METHODS: We retrospectively examined whether specific cerebrovascular variants (vertebral artery hypoplasia and absent/hypoplastic posterior communicating arteries (an incomplete posterior circle of Willis) measured via magnetic resonance angiography) were associated with a diagnosis of hypertension in 220 young adults (<40 years; n=164 primary hypertensive [mean age±SD, 32±6 years] and n=56 [30±6 years] normotensive adults). Whether cerebrovascular variants were associated with lower cerebral blood flow (phase-contrast angiography) was measured in the hypertensive group only (n=146). RESULTS: Binary logistic regression (adjusted for age, sex, and body mass index) showed that vertebral artery hypoplasia with an incomplete posterior circle of Willis was associated with hypertension diagnosis (P<0.001, odds ratio; 11.79 [95% CI, 3.34-41.58]). Vertebral artery hypoplasia plus an incomplete circle of Willis was associated with lower cerebral blood flow in young adults with hypertension (P=0.0172). CONCLUSIONS: Vertebral artery hypoplasia plus an incomplete posterior circle of Willis independently predicts hypertension in young adults suggesting that this variant is not acquired with aging into midlife. Importantly this variant combination was associated with lower cerebral perfusion, which may have long-term consequences on cerebrovascular health in young adults with hypertension.

The corrected left ventricular ejection fraction: a potential new measure of ventricular function.

Left ventricular ejection fraction (LVEF) has a limited role in predicting outlook in heart diseases including heart failure. We quantified the independent geometric factors that determine LVEF using cardiac MRI and sought to provide an improved measure of ventricular function by adjusting for such independent variables. A mathematical model was used to analyse the independent effects of structural variables and myocardial shortening on LVEF. These results informed analysis of cardiac MRI data from 183 patients (53 idiopathic dilated cardiomyopathy (DCM), 36 amyloidosis, 55 hypertensives and 39 healthy controls). Left ventricular volumes, LVEF, wall thickness, internal dimensions and longitudinal and midwall fractional shortening were measured. The modelling demonstrated LVEF increased in a curvilinear manner with increasing mFS and longitudinal shortening and wall thickness but decreased with increasing internal diameter. Controls in the clinical cohort had a mean LVEF 64  ±  7%, hypertensives 66  ±  8%, amyloid 49 ±  16% and DCM 30  ±  11%. The mean end-diastolic wall thickness in controls was 8  ±  1 mm, DCM 8  ±  1 mm, hypertensives 11  ±  3 mm and amyloid 14  ±  3 mm, P < 0.0001). LVEF correlated with absolute wall thickening relative to ventricular size (R2 = 0.766). A regression equation was derived from raw MRI data (R2 = 0.856) and used to 'correct' LVEF (EFc) by adjusting the wall thickness and ventricular size to the mean of the control group. Improved quantification of the effects of geometric changes and strain significantly enhances understanding the myocardial mechanics. The EFc resulted in reclassification of a 'ventricular function' in some individuals and may provide an improved measure of myocardial performance especially in thick-walled, low-volume ventricles.

Contrast circulation in adult fontan patients using MR Time Resolved Angiography: Application for CT pulmonary angiography.

BACKGROUND: When patients with Fontan circulation require a computed tomographic pulmonary angiogram (CTPA), there are significant challenges in achieving adequate contrast opacification due to the altered anatomical connections. This study used Time Resolved Angiography with Interleaved Stochastic Trajectories (TWIST) Magnetic Resonance Angiography (MRA) to examine contrast circulation in a cohort of patients with Fontan circulation who were having routine MRI follow up to inform the contrast timing of any subsequent CT. METHODS: This is a single centre, cross-sectional, observational, retrospective study. The time to peak (TTP) signal intensity from the MRA was recorded using regions of interest on the aorta, pulmonary arteries, cavae and Fontan conduit. Patients were grouped by ejection fraction, global longitudinal strain, indexed stroke volume and cardiac index to examine if these cardiac performance parameters affected the mean TTP. Statistical analysis was performed to find the mean TTP for each of the vessels, which was consequently compared between the different cardiac performance parameters. RESULTS: 35 patients were included in the study. Mean TTP contrast enhancement was 31s in the thoracic aorta, 46s in the right pulmonary artery, 41s in the left pulmonary artery and 55s in the Fontan conduit. Cardiac performance shows no statistically significant relationship to the peak contrast enhancement whether measured by ejection fraction, global longitudinal strain, stroke volume index or cardiac index. CONCLUSION: The mean optimal timing for a single-phase examination of the Fontan circulation, following an upper limb injection, was 55 s following start of contrast injection irrespective of cardiac performance. In TWIST MRA, the IV bolus is 4-5 s duration. A longer bolus is required for CTA, around 20s, suggesting an additional delay will be required. We propose that an optimal single phase CTPA to be protocolled at 70 s following the start of contrast injection, assuming adequate iodinated contrast dose.

Repaired coarctation of the aorta, persistent arterial hypertension and the selfish brain.

BACKGROUND: It has been estimated that 20-30% of repaired aortic coarctation (CoA) patients develop hypertension, with significant cardiovascular morbidity and mortality. Vertebral artery hypoplasia (VAH) with an incomplete posterior circle of Willis (ipCoW; VAH + ipCoW) is associated with increased cerebrovascular resistance before the onset of increased sympathetic nerve activity in borderline hypertensive humans, suggesting brainstem hypoperfusion may evoke hypertension to maintain cerebral blood flow: the "selfish brain" hypothesis. We now assess the "selfish brain" in hypertension post-CoA repair. METHODS: Time-of-flight cardiovascular magnetic resonance angiography from 127 repaired CoA patients (34 ± 14 years, 61% male, systolic blood pressure (SBP) 138 ± 19 mmHg, diastolic blood pressure (DBP) 76 ± 11 mmHg) was compared with 33 normotensive controls (42 ± 14 years, 48% male, SBP 124 ± 10 mmHg, DBP 76 ± 8 mmHg). VAH was defined as < 2 mm and ipCoW as hypoplasia of one or both posterior communicating arteries. RESULTS: VAH + ipCoW was more prevalent in repaired CoA than controls (odds ratio: 5.8 [1.6-20.8], p = 0.007), after controlling for age, sex and body mass index (BMI). VAH + ipCoW was an independent predictor of hypertension (odds ratio: 2.5 [1.2-5.2], p = 0.017), after controlling for age, gender and BMI. Repaired CoA subjects with VAH + ipCoW were more likely to have difficult to treat hypertension (odds ratio: 3.3 [1.01-10.7], p = 0.049). Neither age at time of CoA repair nor any specific repair type were significant predictors of VAH + ipCoW in univariate regression analysis. CONCLUSIONS: VAH + ipCoW predicts arterial hypertension and difficult to treat hypertension in repaired CoA. It is unrelated to age at time of repair or repair type. CoA appears to be a marker of wider congenital cerebrovascular problems. Understanding the "selfish brain" in post-CoA repair may help guide management. JOURNAL SUBJECT CODES: High Blood Pressure; Hypertension; Magnetic Resonance Imaging (MRI); Cardiovascular Surgery; Cerebrovascular Malformations.

Evaluating 3D-printed models of coronary anomalies: a survey among clinicians and researchers at a university hospital in the UK.

OBJECTIVE: To evaluate the feasibility of three-dimensional (3D) printing models of coronary artery anomalies based on cardiac CT data and explore their potential for clinical applications. DESIGN: Cardiac CT datasets of patients with various coronary artery anomalies (n=8) were retrospectively reviewed and processed, reconstructing detailed 3D models to be printed in-house with a desktop 3D printer (Form 2, Formlabs) using white resin. SETTING: A University Hospital (division of cardiology) in the UK. PARTICIPANTS: The CT scans, first and then 3D-printed models were presented to groups of clinicians (n=8) and cardiovascular researchers (n=9). INTERVENTION: Participants were asked to assess different features of the 3D models and to rate the models' overall potential usefulness. OUTCOME MEASURES: Models were rated according to clarity of anatomical detail, insight into the coronary abnormality, overall perceived usefulness and comparison to CT scans. Assessment of model characteristics used Likert-type questions (5-point scale from 'strongly disagree' to 'strongly agree') or a 10-point rating (from 0, lowest, to 10, highest). The questionnaire included a feedback form summarising overall usefulness. Participants' imaging experience (in a number of years) was also recorded. RESULTS: All models were reconstructed and printed successfully, with accurate details showing coronary anatomy (eg, anomalous coronary artery, coronary roofing or coronary aneurysm in a patient with Kawasaki syndrome). All clinicians and researchers provided feedback, with both groups finding the models helpful in displaying coronary artery anatomy and abnormalities, and complementary to viewing 3D CT scans. The clinicians' group, who had substantially more imaging expertise, provided more enthusiastic ratings in terms of models' clarity, usefulness and future use on average. CONCLUSIONS: 3D-printed heart models can be feasibly used to recreate coronary artery anatomy and enhance understanding of coronary abnormalities. Future studies can evaluate their cost-effectiveness, as well as potentially explore other printing techniques and materials.

Left ventricular extracellular volume fraction and atrioventricular interaction in hypertension.

OBJECTIVES: Left atrial enlargement (LAE) predicts cardiovascular morbidity and mortality. Impaired LA function also confers poor prognosis. This study aimed to determine whether left ventricular (LV) interstitial fibrosis is associated with LAE and LA impairment in systemic hypertension. METHODS: Following informed written consent, a prospective observational study of 86 hypertensive patients (49 ± 15 years, 53% male, office SBP 168 ± 30 mmHg, office DBP 97 ± 4 mmHg) and 20 normotensive controls (48 ± 13 years, 55% male, office SBP 130 ± 13 mmHg, office DBP 80 ± 11 mmHg) at 1.5-T cardiovascular magnetic resonance was conducted. Extracellular volume fraction (ECV) was calculated by T1-mapping. LA volume (LAV) was measured with biplane area-length method. LA reservoir, conduit and pump function were calculated with the phasic volumetric method. RESULTS: Indexed LAV correlated with indexed LV mass (R = 0.376, p < 0.0001) and ECV (R = 0.359, p = 0.001). However, ECV was the strongest significant predictor of LAE in multivariate regression analysis (odds ratio [95th confidence interval] 1.24 [1.04-1.48], p = 0.017). Indexed myocardial interstitial volume was associated with significant reductions in LA reservoir (R = -0.437, p < 0.0001) and conduit (R = -0.316, p = 0.003) but not pump (R = -0.167, p = 0.125) function. Multiple linear regression, correcting for age, gender, BMI, BP and diabetes, showed an independent decrease of 3.5% LA total emptying fraction for each 10 ml/m2 increase in myocardial interstitial volume (standard ß coefficient -3.54, p = 0.002). CONCLUSIONS: LV extracellular expansion is associated with LAE and impaired LA reservoir and conduit function. Future studies should identify if targeting diffuse LV fibrosis is beneficial in reverse remodelling of LA structural and functional pathological abnormalities in hypertension. KEY POINTS: • Left atrial enlargement (LAE) and impairment are markers of adverse prognosis in systemic hypertension but their pathophysiology is poorly understood. • Left ventricular extracellular volume fraction was the strongest independent multivariate predictor of LAE and was associated with impaired left atrial reservoir and conduit function. • LV interstitial expansion may play a central role in the pathophysiology of adverse atrioventricular interaction in systemic hypertension.

Noctural dipping status and left ventricular hypertrophy: A cardiac magnetic resonance imaging study.

We investigate the impact of dipper status on cardiac structure with cardiovascular magnetic resonance (CMR). Ambulatory blood pressure monitoring and 1.5T CMR were performed in 99 tertiary hypertension clinic patients. Subgroup analysis by extreme dipper (n = 9), dipper (n = 39), non-dipper (n = 35) and reverse dipper (n = 16) status was performed, matched in age, gender and BMI. Left ventricular (LV) mass was significantly higher for extreme dippers than dippers after correction for covariates (100 ± 6 g/m2 vs 79 ± 3 g/m2 , P = .004). Amongst extreme dippers and dippers (n = 48), indexed LV mass correlated positively with the extent of nocturnal blood pressure dipping (R = .403, P = .005). On post-hoc ANCOVA, the percentage of nocturnal dip had significant effect on indexed LV mass (P = .008), but overall SBP did not (P = .348). In the tertiary setting, we found a larger nocturnal BP drop was associated with more LV hypertrophy. If confirmed in larger studies, this may have implications on nocturnal dosing of anti-hypertensive medications.

Cardiovascular Manifestations and Complications of Loeys-Dietz Syndrome: CT and MR Imaging Findings.

Loeys-Dietz syndrome (LDS) is a recently described genetic connective tissue disorder with a wide spectrum of multisystem involvement. LDS is characterized by rapidly progressive aortic and peripheral arterial aneurysmal disease. LDS and the other inherited aortopathies such as Marfan syndrome have overlapping phenotypic features. However, LDS is characterized by a more aggressive vascular course; patient morbidity and mortality occur at an early age, with complications developing at relatively smaller aortic dimensions. In addition, there is more diffuse arterial involvement in LDS, with a large proportion of patients developing aneurysms of the iliac, mesenteric, and intracranial arteries. Early diagnosis and careful follow-up are essential for ensuring timely intervention in patients with arterial disease. Cross-sectional angiography has an important role in the baseline assessment, follow-up, and evaluation of acute complications of LDS, the thresholds and considerations of which differ from those of other inherited aortopathies. In this article, LDS is compared with other genetic vascular connective tissue disorders. In addition, the genetic, histopathologic, and cardiovascular manifestations of this disease process are reviewed, with a focus on computed tomographic and magnetic resonance imaging findings. Online DICOM image stacks and supplemental material are available for this article. ©RSNA, 2018.

The In Vivo Morphology of Post-Infarct Ventricular Septal Defect and the Implications for Closure.

OBJECTIVES: The aim of this study was to define the dynamic in vivo morphology of post-infarct ventricular septal defect (PIVSD), which has not been previously described in living patients. BACKGROUND: PIVSD is a devastating complication of acute myocardial infarction. METHODS: The anatomic features of PIVSD, as demonstrated by computed tomography or magnetic resonance imaging, were retrospectively reviewed. RESULTS: Thirty-two PIVSDs were assessed, 16 left coronary artery and 16 right coronary artery PIVSDs. PIVSDs were large (mean maximum dimension 26.5 ± 11.5 mm, mean area 5.2 ± 4.2 cm2) and oval (mean eccentricity index 1.7 ± 0.5), with thin margins (diastolic mean thickness 5 mm from the edge of the PIVSD 6.4 ± 3.0mm), and only 22% of PIVSDs were entirely confined to the septum. The defects could be larger in diastole or systole. The stem of the largest available Amplatzer occluder stem (St. Jude Medical, St. Paul, Minnesota) filled only 50% of defects. Patients with small defects may survive without closure. Without closure, those with large defects die. If accepted for closure, PIVSD size and coronary territory did not predict survival >1 year (overall 60%). CONCLUSIONS: This is the first detailed anatomic description of PIVSD in living patients. Defects may be larger in systole or diastole, meaning that single-phase measurement is unsuitable. Its complex nature means that the most commonly available occluder device is frequently unsuitable. Successful closure leads to prolonged survival and should be attempted where possible. This study may lead to improved patient selection, closure techniques, and device design.

Computed tomography in congenital heart disease: how generic principles can be applied to create bespoke protocols in the Fontan circuit.

Cardiac computed tomography (CCT) has become an invaluable cross-sectional imaging modality in congenital heart disease (CHD) patients. However, altered anatomical connections and cardiovascular physiology makes CHD arguably the most challenging area in CCT imaging, which remains a complimentary modality to cardiac magnetic resonance and echocardiography. A bespoke CT protocol is often required to achieve a diagnostic examination; this can be achieved through careful consideration of the basic principles of image acquisition and contrast administration. This article reviews these principles and demonstrates how they can be applied to CCT in CHD using the Fontan circulation as an example.

ECG strain pattern in hypertension is associated with myocardial cellular expansion and diffuse interstitial fibrosis: a multi-parametric cardiac magnetic resonance study.

AIMS: In hypertension, the presence of left ventricular (LV) strain pattern on 12-lead electrocardiogram (ECG) carries adverse cardiovascular prognosis. The underlying mechanisms are poorly understood. We investigated whether hypertensive ECG strain is associated with myocardial interstitial fibrosis and impaired myocardial strain, assessed by multi-parametric cardiac magnetic resonance (CMR). METHODS AND RESULTS: A total of 100 hypertensive patients [50 ± 14 years, male: 58%, office systolic blood pressure (SBP): 170 ± 30 mmHg, office diastolic blood pressure (DBP): 97 ± 14 mmHg) underwent ECG and 1.5T CMR and were compared with 25 normotensive controls (46 ± 14 years, 60% male, SBP: 124 ± 8 mmHg, DBP: 76 ± 7 mmHg). Native T1 and extracellular volume fraction (ECV) were calculated with the modified look-locker inversion-recovery sequence. Myocardial strain values were estimated with voxel-tracking software. ECG strain (n = 20) was associated with significantly higher indexed LV mass (LVM) (119 ± 32 vs. 80 ± 17 g/m2, P < 0.05) and ECV (30 ± 4 vs. 27 ± 3%, P < 0.05) compared with hypertensive subjects without ECG strain (n = 80). ECG strain subjects had significantly impaired circumferential strain compared with hypertensive subjects without ECG strain and controls (-15.2 ± 4.7 vs. -17.0 ± 3.3 vs. -17.3 ± 2.4%, P < 0.05, respectively). In subgroup analysis, comparing ECG strain subjects to hypertensive subjects with elevated LVM but no ECG strain, a significantly higher ECV (30 ± 4 vs. 28 ± 3%, P < 0.05) was still observed. Indexed LVM was the only variable independently associated with ECG strain in multivariate logistic regression analysis [odds ratio (95th confidence interval): 1.07 (1.02-1.12), P < 0.05). CONCLUSION: In hypertension, ECG strain is a marker of advanced LVH associated with increased interstitial fibrosis and associated with significant myocardial circumferential strain impairment.

Hypertensive heart disease versus hypertrophic cardiomyopathy: multi-parametric cardiovascular magnetic resonance discriminators when end-diastolic wall thickness ≥ 15 mm.

OBJECTIVES: European guidelines state left ventricular (LV) end-diastolic wall thickness (EDWT) ≥15mm suggests hypertrophic cardiomyopathy (HCM), but distinguishing from hypertensive heart disease (HHD) is challenging. We identify cardiovascular magnetic resonance (CMR) predictors of HHD over HCM when EDWT ≥15mm. METHODS: 2481 consecutive clinical CMRs between 2014 and 2015 were reviewed. 464 segments from 29 HCM subjects with EDWT ≥15mm but without other cardiac abnormality, hypertension or renal impairment were analyzed. 432 segments from 27 HHD subjects with EDWT ≥15mm but without concomitant cardiac pathology were analyzed. Magnitude and location of maximal EDWT, presence of late gadolinium enhancement (LGE), LV asymmetry (>1.5-fold opposing segment) and systolic anterior motion of the mitral valve (SAM) were measured. Multivariate logistic regression was performed. Significance was defined as p<0.05. RESULTS: HHD and HCM cohorts were age-/gender-matched. HHD had significantly increased indexed LV mass (110±27g/m2 vs. 91±31g/m2, p=0.016) but no difference in site or magnitude of maximal EDWT. Mid-wall LGE was significantly more prevalent in HCM. Elevated indexed LVM, mid-wall LGE and absence of SAM were significant multivariate predictors of HHD, but LV asymmetry was not. CONCLUSIONS: Increased indexed LV mass, absence of mid-wall LGE and absence of SAM are better CMR discriminators of HHD from HCM than EDWT ≥15mm. KEY POINTS: • Hypertrophic cardiomyopathy (HCM) is often diagnosed with end-diastolic wall thickness ≥15mm. • Hypertensive heart disease (HHD) can be difficult to distinguish from HCM. • Retrospective case-control study showed that location and magnitude of EDWT are poor discriminators. • Increased left ventricular mass and midwall fibrosis are independent predictors of HHD. • Cardiovascular magnetic resonance parameters facilitate a better discrimination between HHD and HCM.

Comprehensive First-Line Magnetic Resonance Imaging in Hypertension: Experience From a Single-Center Tertiary Referral Clinic.

European guidelines recommend that patients with hypertension be assessed for asymptomatic organ damage and secondary causes. The authors propose that a single magnetic resonance imaging (MRI) scan can provide comprehensive first-line imaging of patients assessed via a specialist hypertension clinic. A total of 200 patients (56% male, aged 51±15 years, office BP 168±30/96±16 mm Hg) underwent MRI of the heart, kidneys, renal arteries, adrenals and aorta. Comparisons were made with other imaging modalities where available. A total of 61% had left ventricular hypertrophy (LVH), 14% had reduced ejection fraction, and 15 patients had myocardial infarcts. Echocardiography overdiagnosed LVH in 15% of patients and missed LVH in 14%. Secondary causes were identified in 14.5% of patients: 12 adrenal masses, 10 renal artery stenoses, seven thyroid abnormalities, one aortic coarctation, one enlarged pituitary gland, one polycystic kidney disease, and one renal coloboma syndrome. This comprehensive MRI protocol is an effective method of screening for asymptomatic organ damage and secondary causes of hypertension.